#include<bits/stdc++.h>
#define maxn 100005
using namespace std;
int n,m;
vector<int>p[maxn];
vector<int>v[maxn];
queue<int>q;
bool u[maxn],w[maxn];
void solve(int x);
int main(){
	cin >> n >> m;
	for(int i = 1;i <= m;i++){
		int x,y;
		cin >> x >> y;
		p[x].push_back(y);
		v[x].push_back(y);
	}
	u[1] = true;
	solve(1);
	cout << endl;
	w[1] = true;
	q.push(1);
	while(!q.empty()){
		int x = q.front();
		q.pop();
		cout << x << " ";
		for(int i = 0,sz = v[x].size();i < sz;i++){
			if(!w[v[x][i]]){
				w[v[x][i]] = true;
				q.push(v[x][i]);
			}
		}
	}
	return 0;
}
void solve(int x){
	cout << x << " ";
	for(int i = 0,sz = p[x].size();i < sz;i++){
		if(!u[p[x][i]]){
			u[p[x][i]] = true;
			solve(p[x][i]);
		}
	}
}